icon: programmatic Redline app icon (icns + generator script)

Ben-reported: picker opened on every activation. AppModel.init set region = nil and never
read UserDefaults back; saving worked, every launch forgot it. init now loads via
loadPersistedRegion() (decode + isStillValid). Selftest phase 2 writes a known region,
reloads through the same path, asserts the rect, restores the user's stored value.
Coordinator ran it: PICKER-SELFTEST PASS + REGION-PERSIST PASS, 90/90 tests green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Info.plist

@@ -2,10 +2,14 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
+	<!-- Identity invariants: CFBundleIdentifier stays ai.flowmaster.shotdeck and
+	     CFBundleExecutable stays Shotdeck. Changing either one invalidates the
+	     user's existing Screen Recording grant. CFBundleName is the user-facing
+	     product name only. -->
 	<key>CFBundleIdentifier</key>
 	<string>ai.flowmaster.shotdeck</string>
 	<key>CFBundleName</key>
-	<string>Shotdeck</string>
+	<string>Redline</string>
 	<key>CFBundleExecutable</key>
 	<string>Shotdeck</string>
 	<key>CFBundlePackageType</key>
@@ -14,6 +18,8 @@
 	<string>0.1.0</string>
 	<key>CFBundleVersion</key>
 	<string>1</string>
+	<key>CFBundleIconFile</key>
+	<string>AppIcon</string>
 	<key>LSUIElement</key>
 	<true/>
 	<key>LSMinimumSystemVersion</key>

README.md

@@ -1,4 +1,4 @@
-# Shotdeck
+# Redline
 
 A macOS menu-bar app that captures a remembered screen region, builds a one-screenshot-per-page PDF, AirDrops it to an iPad for markup, then watches for the annotated file to come back.
 
@@ -18,5 +18,5 @@ The grant is bound to the bundle identifier `ai.flowmaster.shotdeck` plus the co
 ```bash
 swift build && swift test
 ./scripts/build-app.sh          # signed .app for daily use
-open .build/Shotdeck.app
+open .build/Redline.app
 ```

Sources/Shotdeck/AppModel.swift

@@ -72,7 +72,7 @@ public final class AppModel {
             captures: [],
             pdfFileName: nil
         )
-        self.region = nil
+        self.region = Self.loadPersistedRegion()
         self.screenRecordingGranted = ScreenCapturer.isScreenRecordingGranted
         // Seeded from FolderSettings.resolve() via resolvedAppSupportPaths — never .standard().
         let folders = FolderSettings.resolve()
@@ -237,6 +237,14 @@ public final class AppModel {
         NSWorkspace.shared.open(url)
     }
 
+    static func loadPersistedRegion() -> CaptureRegion? {
+        guard let data = UserDefaults.standard.data(forKey: CaptureRegion.defaultsKey),
+              let decoded = try? JSONDecoder().decode(CaptureRegion.self, from: data),
+              decoded.isStillValid
+        else { return nil }
+        return decoded
+    }
+
     private func persistRegion(_ picked: CaptureRegion) {
         replaceRegion(picked)
         if let encoded = try? JSONEncoder().encode(picked) {

Sources/Shotdeck/MenuBarView.swift

@@ -128,7 +128,7 @@ struct MenuBarView: View {
             Button {
                 NSApp.terminate(nil)
             } label: {
-                actionLabel("Quit Shotdeck")
+                actionLabel("Quit Redline")
             }
         }
         .buttonStyle(.plain)

Sources/Shotdeck/PickerSelfTest.swift

@@ -0,0 +1,215 @@
+import AppKit
+import Darwin
+import Foundation
+import ShotdeckCore
+
+/// In-process self-test for the region picker, driven by `SHOTDECK_PICKER_SELFTEST`.
+/// Posts synthetic mouse events through `NSApp.postEvent` only — never CGEventPost/taps.
+@MainActor
+enum PickerSelfTest {
+    private static let pointA = NSPoint(x: 200, y: 300)
+    private static let pointB = NSPoint(x: 600, y: 600)
+    private static let dragSteps = 6
+
+    /// Called from `main.swift` before `ShotdeckApp.main()`. Returns immediately when the
+    /// env var is unset; otherwise waits for launch, drives the production picker, and `exit`s.
+    static func runIfRequested() {
+        guard let raw = ProcessInfo.processInfo.environment["SHOTDECK_PICKER_SELFTEST"],
+              !raw.isEmpty
+        else { return }
+
+        let output = URL(fileURLWithPath: raw, isDirectory: true)
+        // Hop onto a plain main-queue turn after NSApp starts. Nested run loops
+        // from a Swift Task do not drain NSApp's event queue.
+        DispatchQueue.main.async {
+            MainActor.assumeIsolated {
+                execute(outputDirectory: output)
+            }
+        }
+    }
+
+    private static func execute(outputDirectory: URL) {
+        do {
+            try FileManager.default.createDirectory(
+                at: outputDirectory,
+                withIntermediateDirectories: true
+            )
+        } catch {
+            fail(expected: expectedLabel(), got: "could not create output dir: \(error)")
+        }
+
+        guard let screen = NSScreen.screens.first(where: { $0.frame.contains(pointA) })
+            ?? NSScreen.screens.first
+        else {
+            fail(expected: expectedLabel(), got: "no NSScreen")
+        }
+
+        let appKitRect = CGRect(
+            x: min(pointA.x, pointB.x),
+            y: min(pointA.y, pointB.y),
+            width: abs(pointB.x - pointA.x),
+            height: abs(pointB.y - pointA.y)
+        ).intersection(screen.frame)
+        let expected = CaptureRegion.fromAppKit(rect: appKitRect, on: screen)
+
+        let picker = RegionPickerController()
+        var result: CaptureRegion??
+        picker.pick { region in
+            result = .some(region)
+        }
+
+        guard let overlay = overlayWindow(containing: pointA) else {
+            fail(expected: format(expected.rect), got: "no overlay window after pick()")
+        }
+        overlay.makeKey()
+
+        var eventNumber = 1
+        func post(_ type: NSEvent.EventType, at screenPoint: NSPoint, clickCount: Int) {
+            let locationInWindow = overlay.convertPoint(fromScreen: screenPoint)
+            guard let event = NSEvent.mouseEvent(
+                with: type,
+                location: locationInWindow,
+                modifierFlags: [],
+                timestamp: ProcessInfo.processInfo.systemUptime,
+                windowNumber: overlay.windowNumber,
+                context: nil,
+                eventNumber: eventNumber,
+                clickCount: clickCount,
+                pressure: 1
+            ) else {
+                fail(expected: format(expected.rect), got: "NSEvent.mouseEvent(\(type.rawValue)) returned nil")
+            }
+            eventNumber += 1
+            NSApp.postEvent(event, atStart: false)
+            // Local monitors run during NSApp.sendEvent (production dispatch),
+            // not during nextEvent dequeue. Drive that same path here.
+            NSApp.sendEvent(event)
+        }
+
+        post(.leftMouseDown, at: pointA, clickCount: 1)
+        for step in 1...(dragSteps / 2) {
+            post(.leftMouseDragged, at: interpolate(step), clickCount: 0)
+        }
+
+        writeOverlayBitmap(overlay, to: outputDirectory.appendingPathComponent("overlay-middrag.png"))
+
+        for step in ((dragSteps / 2) + 1)...dragSteps {
+            post(.leftMouseDragged, at: interpolate(step), clickCount: 0)
+        }
+        post(.leftMouseUp, at: pointB, clickCount: 1)
+
+        guard let wrapped = result else {
+            fail(expected: format(expected.rect), got: "completion never fired")
+        }
+        guard let got = wrapped else {
+            fail(expected: format(expected.rect), got: "nil")
+        }
+
+        if got.rect != expected.rect {
+            fail(expected: format(expected.rect), got: format(got.rect))
+        }
+
+        print("PICKER-SELFTEST PASS rect=\(format(got.rect))")
+        fflush(stdout)
+
+        runRegionPersistPhase()
+        exit(0)
+    }
+
+    /// Phase 2: writes a known region under `CaptureRegion.defaultsKey`, reloads it through
+    /// `AppModel.loadPersistedRegion()` (the same path init uses), then restores whatever
+    /// value was stored before so a real picked region is untouched.
+    private static func runRegionPersistPhase() {
+        let defaults = UserDefaults.standard
+        let previous = defaults.data(forKey: CaptureRegion.defaultsKey)
+
+        let known = CaptureRegion(
+            displayID: CGMainDisplayID(),
+            rect: CGRect(x: 10, y: 10, width: 100, height: 100),
+            capturedScale: 2.0
+        )
+        var failure: String?
+        if let encoded = try? JSONEncoder().encode(known) {
+            defaults.set(encoded, forKey: CaptureRegion.defaultsKey)
+            if let loaded = AppModel.loadPersistedRegion() {
+                if loaded.rect != known.rect {
+                    failure = "expected=\(format(known.rect)) got=\(format(loaded.rect))"
+                }
+            } else {
+                failure = "loadPersistedRegion returned nil"
+            }
+        } else {
+            failure = "could not encode CaptureRegion"
+        }
+
+        if let previous {
+            defaults.set(previous, forKey: CaptureRegion.defaultsKey)
+        } else {
+            defaults.removeObject(forKey: CaptureRegion.defaultsKey)
+        }
+
+        if let failure {
+            print("REGION-PERSIST FAIL \(failure)")
+            fflush(stdout)
+            exit(1)
+        }
+        print("REGION-PERSIST PASS")
+        fflush(stdout)
+    }
+
+    private static func interpolate(_ step: Int) -> NSPoint {
+        let t = CGFloat(step) / CGFloat(dragSteps)
+        return NSPoint(
+            x: pointA.x + (pointB.x - pointA.x) * t,
+            y: pointA.y + (pointB.y - pointA.y) * t
+        )
+    }
+
+    private static func overlayWindow(containing point: NSPoint) -> RegionPickerWindow? {
+        let overlays = NSApp.windows.compactMap { $0 as? RegionPickerWindow }
+        return overlays.first(where: { $0.coveringScreen.frame.contains(point) }) ?? overlays.first
+    }
+
+    private static func writeOverlayBitmap(_ overlay: RegionPickerWindow, to url: URL) {
+        guard let view = overlay.contentView else {
+            fail(expected: expectedLabel(), got: "overlay has no contentView")
+        }
+        overlay.layoutIfNeeded()
+        view.layoutSubtreeIfNeeded()
+        view.display()
+        let bounds = view.bounds
+        guard let rep = view.bitmapImageRepForCachingDisplay(in: bounds) else {
+            fail(expected: expectedLabel(), got: "bitmapImageRepForCachingDisplay failed")
+        }
+        view.cacheDisplay(in: bounds, to: rep)
+        guard let png = rep.representation(using: .png, properties: [:]) else {
+            fail(expected: expectedLabel(), got: "PNG encode failed")
+        }
+        do {
+            try png.write(to: url)
+        } catch {
+            fail(expected: expectedLabel(), got: "could not write \(url.path): \(error)")
+        }
+        print(url.path)
+        fflush(stdout)
+    }
+
+    private static func expectedLabel() -> String {
+        format(CGRect(
+            x: min(pointA.x, pointB.x),
+            y: min(pointA.y, pointB.y),
+            width: abs(pointB.x - pointA.x),
+            height: abs(pointB.y - pointA.y)
+        ))
+    }
+
+    private static func format(_ rect: CGRect) -> String {
+        "(\(rect.origin.x), \(rect.origin.y), \(rect.width), \(rect.height))"
+    }
+
+    private static func fail(expected: String, got: String) -> Never {
+        print("PICKER-SELFTEST FAIL expected=\(expected) got=\(got)")
+        fflush(stdout)
+        exit(1)
+    }
+}

Sources/Shotdeck/RegionPickerController.swift

@@ -48,20 +48,27 @@ public final class RegionPickerController {
             matching: [.leftMouseDown, .leftMouseDragged, .leftMouseUp, .keyDown]
         ) { [weak self] event in
             guard let self else { return event }
-            // NSEvent is not Sendable; lift the two Sendable fields the handler
-            // needs. Mouse geometry is read from NSEvent.mouseLocation on the
-            // main thread inside the isolated methods, per spec.
+            // NSEvent is not Sendable; lift Sendable fields the handler needs.
+            // Prefer the event's window-local point converted to global AppKit
+            // coordinates; NSEvent.mouseLocation is only a fallback.
+            // keyCode is only valid on key events — reading it on a mouse event raises.
             let type = event.type
-            let keyCode = event.keyCode
+            let keyCode: UInt16 = (type == .keyDown) ? event.keyCode : 0
+            let locationInWindow = event.locationInWindow
+            let windowNumber = event.windowNumber
             let consume = MainActor.assumeIsolated {
-                self.handle(type: type, keyCode: keyCode)
+                let location = self.globalAppKitLocation(
+                    locationInWindow: locationInWindow,
+                    windowNumber: windowNumber
+                )
+                return self.handle(type: type, keyCode: keyCode, location: location)
             }
             return consume ? nil : event
         }
     }
 
     /// Returns `true` when the event should be swallowed.
-    private func handle(type: NSEvent.EventType, keyCode: UInt16) -> Bool {
+    private func handle(type: NSEvent.EventType, keyCode: UInt16, location: NSPoint?) -> Bool {
         switch type {
         case .keyDown:
             if keyCode == 53 { // kVK_Escape
@@ -70,21 +77,21 @@ public final class RegionPickerController {
             }
             return false
         case .leftMouseDown:
-            handleMouseDown()
+            handleMouseDown(location: location)
             return false
         case .leftMouseDragged:
-            handleMouseDragged()
+            handleMouseDragged(location: location)
             return false
         case .leftMouseUp:
-            handleMouseUp()
+            handleMouseUp(location: location)
             return false
         default:
             return false
         }
     }
 
-    private func handleMouseDown() {
-        let point = NSEvent.mouseLocation
+    private func handleMouseDown(location: NSPoint?) {
+        let point = location ?? NSEvent.mouseLocation
         dragStart = point
         startScreen = NSScreen.screens.first(where: { $0.frame.contains(point) })
             ?? NSScreen.screens.first
@@ -99,17 +106,17 @@ public final class RegionPickerController {
         }
     }
 
-    private func handleMouseDragged() {
+    private func handleMouseDragged(location: NSPoint?) {
         guard dragStart != nil, startScreen != nil else { return }
-        applyLiveSelection()
+        applyLiveSelection(current: location)
     }
 
-    private func handleMouseUp() {
+    private func handleMouseUp(location: NSPoint?) {
         guard let startScreen else {
             dragStart = nil
             return
         }
-        guard let rect = currentClampedRect(), rect.width >= 8, rect.height >= 8 else {
+        guard let rect = currentClampedRect(current: location), rect.width >= 8, rect.height >= 8 else {
             // Mis-click: reset drag state, leave every window open and fully dimmed.
             dragStart = nil
             self.startScreen = nil
@@ -122,8 +129,8 @@ public final class RegionPickerController {
         finish(region: region)
     }
 
-    private func applyLiveSelection() {
-        guard let startScreen, let rect = currentClampedRect() else { return }
+    private func applyLiveSelection(current: NSPoint?) {
+        guard let startScreen, let rect = currentClampedRect(current: current) else { return }
         let local = Self.localRect(from: rect, on: startScreen)
         let text = "\(Int(rect.width)) x \(Int(rect.height))"
         window(for: startScreen)?.updateSelection(localRect: local, sizeText: text)
@@ -134,9 +141,9 @@ public final class RegionPickerController {
 
     /// Normalize the drag (so bottom-right → up-left is not misjudged) then clamp
     /// to the screen the gesture started on — never selects across displays.
-    private func currentClampedRect() -> CGRect? {
+    private func currentClampedRect(current: NSPoint?) -> CGRect? {
         guard let dragStart, let startScreen else { return nil }
-        let current = NSEvent.mouseLocation
+        let current = current ?? NSEvent.mouseLocation
         let normalized = CGRect(
             x: min(dragStart.x, current.x),
             y: min(dragStart.y, current.y),
@@ -146,6 +153,21 @@ public final class RegionPickerController {
         return normalized.intersection(startScreen.frame)
     }
 
+    /// Convert a monitored event's `locationInWindow` into global AppKit coordinates
+    /// (bottom-left origin, matching `NSEvent.mouseLocation` / `NSScreen.frame`).
+    private func globalAppKitLocation(locationInWindow: NSPoint, windowNumber: Int) -> NSPoint? {
+        if let window = windows.first(where: { $0.windowNumber == windowNumber }) {
+            return window.convertPoint(toScreen: locationInWindow)
+        }
+        if windowNumber != 0, let window = NSApp.window(withWindowNumber: windowNumber) {
+            return window.convertPoint(toScreen: locationInWindow)
+        }
+        if windowNumber == 0 {
+            return locationInWindow
+        }
+        return nil
+    }
+
     private func window(for screen: NSScreen) -> RegionPickerWindow? {
         windows.first { $0.coveringScreen === screen }
     }

Sources/Shotdeck/RegionPickerWindow.swift

@@ -29,6 +29,7 @@ final class RegionPickerWindow: NSPanel {
         becomesKeyOnlyIfNeeded = false
         animationBehavior = .none
         collectionBehavior = [.canJoinAllSpaces, .fullScreenAuxiliary, .stationary]
+        acceptsMouseMovedEvents = true
         contentView = pickerView
     }
 
@@ -53,6 +54,8 @@ private final class RegionPickerView: NSView {
 
     override var isOpaque: Bool { false }
     override var acceptsFirstResponder: Bool { true }
+    // Accessory-app trap: first click on an inactive overlay is first-mouse and is dropped unless accepted.
+    override func acceptsFirstMouse(for event: NSEvent?) -> Bool { true }
 
     override func draw(_ dirtyRect: NSRect) {
         super.draw(dirtyRect)

Sources/Shotdeck/SendController.swift

@@ -18,7 +18,7 @@ extension AppModel: SendCapable {
         let finalURL = outboxDir.appendingPathComponent(fileName)
         // Same directory as the final target so the rename below is same-volume (atomic).
         let tempURL = outboxDir.appendingPathComponent(".shotdeck-\(UUID().uuidString).pdf")
-        let title = "Shotdeck – \(DubaiTime.stamp(workingSession.createdAt))"
+        let title = "Redline – \(DubaiTime.stamp(workingSession.createdAt))"
 
         do {
             // D-13: build off the main actor. Only Sendable values cross into the

Sources/Shotdeck/SettingsView.swift

@@ -5,39 +5,79 @@ import ShotdeckCore
 struct SettingsView: View {
     @Environment(AppModel.self) private var model
 
+    private let labelWidth: CGFloat = 104
+
     var body: some View {
-        Form {
-            Section("Hotkey") {
-                LabeledContent("Capture", value: "⌥⇧2 — fixed in this version")
+        Grid(alignment: .leading, horizontalSpacing: 12, verticalSpacing: 10) {
+            GridRow {
+                Text("Hotkey")
+                    .font(.headline)
+                    .frame(maxWidth: .infinity, alignment: .leading)
+                    .gridCellColumns(2)
             }
-            Section("Folders") {
-                LabeledContent("Watch folder") {
-                    HStack(spacing: 8) {
-                        Text(model.watchFolderURL.path)
-                            .lineLimit(1)
-                            .truncationMode(.middle)
-                            .foregroundStyle(.secondary)
-                        Button("Choose…") { model.chooseWatchFolder() }
-                    }
-                }
-                LabeledContent("Output folder") {
-                    HStack(spacing: 8) {
-                        Text(model.outboxURL.path)
-                            .lineLimit(1)
-                            .truncationMode(.middle)
-                            .foregroundStyle(.secondary)
-                        Button("Choose…") { model.chooseOutboxFolder() }
-                    }
+
+            GridRow(alignment: .firstTextBaseline) {
+                fieldLabel("Capture")
+                Text("⌥⇧2 — fixed in this version")
+                    .foregroundStyle(.secondary)
+                    .lineLimit(1)
+                    .frame(maxWidth: .infinity, alignment: .leading)
+                    .frame(minHeight: 22, alignment: .leading)
+            }
+
+            GridRow {
+                Text("Folders")
+                    .font(.headline)
+                    .frame(maxWidth: .infinity, alignment: .leading)
+                    .gridCellColumns(2)
+                    .padding(.top, 6)
+            }
+
+            GridRow(alignment: .center) {
+                fieldLabel("Watch folder")
+                folderValue(path: model.watchFolderURL.path) {
+                    model.chooseWatchFolder()
                 }
             }
-            Section {
+
+            GridRow(alignment: .center) {
+                fieldLabel("Output folder")
+                folderValue(path: model.outboxURL.path) {
+                    model.chooseOutboxFolder()
+                }
+            }
+
+            GridRow {
                 Button("Reveal spool folder") { model.openSpoolFolder() }
+                    .gridCellColumns(2)
+                    .frame(maxWidth: .infinity, alignment: .leading)
+                    .padding(.top, 4)
             }
         }
-        .padding()
-        .frame(width: 360)
+        .padding(16)
+        .frame(minWidth: 320, idealWidth: 360, maxWidth: 360, alignment: .leading)
         .controlSize(.small)
     }
+
+    private func fieldLabel(_ title: String) -> some View {
+        Text(title)
+            .lineLimit(1)
+            .frame(width: labelWidth, alignment: .trailing)
+            .gridColumnAlignment(.trailing)
+            .frame(minHeight: 22, alignment: .trailing)
+    }
+
+    private func folderValue(path: String, choose: @escaping () -> Void) -> some View {
+        HStack(spacing: 8) {
+            Text(path)
+                .lineLimit(1)
+                .truncationMode(.middle)
+                .foregroundStyle(.secondary)
+                .frame(maxWidth: .infinity, alignment: .leading)
+            Button("Choose…") { choose() }
+        }
+        .frame(minHeight: 22)
+    }
 }
 
 extension AppModel: SettingsWindowPresenting {
@@ -51,7 +91,7 @@ extension AppModel: SettingsWindowPresenting {
         }
         let hosting = NSHostingController(rootView: SettingsView().environment(self))
         let window = NSWindow(contentViewController: hosting)
-        window.title = "Shotdeck Settings"
+        window.title = "Redline Settings"
         window.styleMask = [.titled, .closable]
         window.isReleasedWhenClosed = false
         window.center()

Sources/Shotdeck/main.swift

@@ -7,6 +7,9 @@ import ShotdeckCore
 if ProcessInfo.processInfo.environment["SHOTDECK_SNAPSHOT_DIR"] != nil {
     MainActor.assumeIsolated { PanelSnapshot.runIfRequested() }
 }
+if ProcessInfo.processInfo.environment["SHOTDECK_PICKER_SELFTEST"] != nil {
+    MainActor.assumeIsolated { PickerSelfTest.runIfRequested() }
+}
 ShotdeckApp.main()
 
 struct ShotdeckApp: App {
@@ -24,7 +27,7 @@ struct ShotdeckApp: App {
                     Text(count).font(.system(size: 11, weight: .semibold))
                 }
             }
-            .accessibilityLabel("Shotdeck")
+            .accessibilityLabel("Redline")
         }
         .menuBarExtraStyle(.window)
     }
@@ -57,7 +60,7 @@ final class AppDelegate: NSObject, NSApplicationDelegate {
             // Safe: temp-dir creation for a path this process controls cannot legitimately fail.
             let fallback = try! AppSupportPaths(root: fallbackRoot, outbox: tmp, watchFolder: tmp)
             let model = try! makeModel(paths: fallback)
-            model.setStatus("Shotdeck could not access its storage folder. Captures will not persist.")
+            model.setStatus("Redline could not access its storage folder. Captures will not persist.")
             return model
         }
     }

Sources/ShotdeckCore/Model/ShotdeckError.swift

@@ -16,7 +16,7 @@ public enum ShotdeckError: Error, LocalizedError, Sendable {
         case .screenRecordingNotGranted:
             return "Screen Recording is turned off. Grant it in System Settings to capture."
         case .noRegionRemembered:
-            return "No capture region is set. Choose 'Re-select area' from the Shotdeck menu."
+            return "No capture region is set. Choose 'Re-select area' from the Redline menu."
         case .displayNoLongerConnected:
             return "The display used for capture is no longer connected."
         case .captureFailed(let underlying):

Sources/ShotdeckCore/PDF/PDFComposer.swift

@@ -71,7 +71,7 @@ public struct PDFComposer: Sendable {
     }
 
     public static func fileName(for session: CaptureSession) -> String {
-        "Shotdeck-\(DubaiTime.fileStamp(session.createdAt)).pdf"
+        "Redline-\(DubaiTime.fileStamp(session.createdAt)).pdf"
     }
 
     private static func writePDF(
@@ -86,7 +86,7 @@ public struct PDFComposer: Sendable {
         }
 
         let auxiliaryInfo: [String: Any] = [
-            kCGPDFContextCreator as String: "Shotdeck",
+            kCGPDFContextCreator as String: "Redline",
             kCGPDFContextTitle as String: title,
             kCGPDFContextSubject as String: sessionID.uuidString.lowercased(),
         ]

Sources/ShotdeckCore/Returns/AnnotationInspector.swift

@@ -93,16 +93,19 @@ public enum AnnotationInspector {
         )
     }
 
-    /// True when this PDF was produced by Shotdeck. Creator attribute is authoritative;
+    /// True when this PDF was produced by this app. Creator attribute is authoritative;
     /// the filename fallback applies ONLY when the creator attribute is absent.
+    /// Accepts both the current product name ("Redline") and the legacy name ("Shotdeck")
+    /// so PDFs already on the iPad or in Downloads are still detected.
     public static func isShotdeckDocument(_ document: PDFDocument) -> Bool {
         if let creator = document.documentAttributes?[PDFDocumentAttribute.creatorAttribute] as? String {
-            return creator == "Shotdeck"          // present creator is authoritative, full stop
+            // Present creator is authoritative, full stop.
+            return creator == "Redline" || creator == "Shotdeck"
         }
         // Creator ABSENT (some apps rewrite metadata on save) -> filename fallback only here.
         guard let name = document.documentURL?.lastPathComponent else { return false }
         // .lastPathComponent on a file URL is already percent-decoded; do not use .absoluteString.
-        return name.wholeMatch(of: /^Shotdeck-\d{8}-\d{6}( \d+)?\.pdf$/) != nil
+        return name.wholeMatch(of: /^(Redline|Shotdeck)-\d{8}-\d{6}( \d+)?\.pdf$/) != nil
         // Case-sensitive by construction (Swift Regex literals are case-sensitive by default).
         // The optional "( \d+)?" is macOS's duplicate-name suffix AirDrop adds when a file of
         // the same name already exists in the watch folder — the normal case for a return.

Sources/ShotdeckCore/Returns/ReturnWatcher.swift

@@ -60,7 +60,7 @@ public actor ReturnWatcher {
     }
 
     /// Scans the watch folder once, immediately, without waiting for an event. Every
-    /// recognized, stable, openable Shotdeck PDF present is (re-)inspected and (re-)recorded
+    /// recognized, stable, openable Redline/Shotdeck PDF present is (re-)inspected and (re-)recorded
     /// into the ledger; returns exactly the documents processed in this call.
     @discardableResult
     public func scanNow() async throws -> [ReturnedDocument] {

Tests/ShotdeckCoreTests/AnnotationInspectorTests.swift

@@ -371,6 +371,72 @@ func i19b_presentNonShotdeckCreatorBeatsMatchingFilename() throws {
     #expect(AnnotationInspector.isShotdeckDocument(reopened) == false)
 }
 
+@Test("I-19c Present Redline creator is recognized")
+func i19c_presentRedlineCreatorIsRecognized() throws {
+    let (paths, cleanup) = try makeCasePaths()
+    defer { try? FileManager.default.removeItem(at: cleanup) }
+
+    let pdfURL = paths.watchFolder.appendingPathComponent("Redline-20260830-134219.pdf")
+    try makePDF(at: pdfURL, pageCount: 1, creator: "Redline")
+    let reopened = try #require(PDFDocument(url: pdfURL))
+    #expect(AnnotationInspector.isShotdeckDocument(reopened) == true)
+}
+
+@Test("I-19d Present legacy Shotdeck creator is still recognized")
+func i19d_presentLegacyShotdeckCreatorIsStillRecognized() throws {
+    let (paths, cleanup) = try makeCasePaths()
+    defer { try? FileManager.default.removeItem(at: cleanup) }
+
+    let pdfURL = paths.watchFolder.appendingPathComponent("Shotdeck-20260830-134220.pdf")
+    try makePDF(at: pdfURL, pageCount: 1, creator: "Shotdeck")
+    let reopened = try #require(PDFDocument(url: pdfURL))
+    #expect(AnnotationInspector.isShotdeckDocument(reopened) == true)
+}
+
+@Test("I-19e Absent creator falls back to Redline filename")
+func i19e_absentCreatorFallsBackToRedlineFilename() throws {
+    let (paths, cleanup) = try makeCasePaths()
+    defer { try? FileManager.default.removeItem(at: cleanup) }
+
+    let pdfURL = paths.watchFolder.appendingPathComponent("Redline-20260830-134221.pdf")
+    try makePDF(at: pdfURL, pageCount: 1, creator: nil)
+    let reopened = try #require(PDFDocument(url: pdfURL))
+    #expect(AnnotationInspector.isShotdeckDocument(reopened) == true)
+}
+
+@Test("I-19f Absent creator falls back to legacy Shotdeck filename")
+func i19f_absentCreatorFallsBackToLegacyShotdeckFilename() throws {
+    let (paths, cleanup) = try makeCasePaths()
+    defer { try? FileManager.default.removeItem(at: cleanup) }
+
+    let pdfURL = paths.watchFolder.appendingPathComponent("Shotdeck-20260830-134222.pdf")
+    try makePDF(at: pdfURL, pageCount: 1, creator: nil)
+    let reopened = try #require(PDFDocument(url: pdfURL))
+    #expect(AnnotationInspector.isShotdeckDocument(reopened) == true)
+}
+
+@Test("I-19g Absent creator falls back to Redline duplicate-name suffix")
+func i19g_absentCreatorFallsBackToRedlineDuplicateNameSuffix() throws {
+    let (paths, cleanup) = try makeCasePaths()
+    defer { try? FileManager.default.removeItem(at: cleanup) }
+
+    let pdfURL = paths.watchFolder.appendingPathComponent("Redline-20260830-134223 2.pdf")
+    try makePDF(at: pdfURL, pageCount: 1, creator: nil)
+    let reopened = try #require(PDFDocument(url: pdfURL))
+    #expect(AnnotationInspector.isShotdeckDocument(reopened) == true)
+}
+
+@Test("I-19h Present non-product creator beats a matching Redline filename")
+func i19h_presentNonProductCreatorBeatsMatchingRedlineFilename() throws {
+    let (paths, cleanup) = try makeCasePaths()
+    defer { try? FileManager.default.removeItem(at: cleanup) }
+
+    let pdfURL = paths.watchFolder.appendingPathComponent("Redline-20260830-134224.pdf")
+    try makePDF(at: pdfURL, pageCount: 1, creator: "Preview")
+    let reopened = try #require(PDFDocument(url: pdfURL))
+    #expect(AnnotationInspector.isShotdeckDocument(reopened) == false)
+}
+
 private func expectSinglePageMark(
     _ subtype: PDFAnnotationSubtype,
     bounds: CGRect,

Tests/ShotdeckCoreTests/PDFComposerTests.swift

@@ -499,7 +499,7 @@ func documentAttributesRoundTrip() throws {
     )
     let document = try openDocument(output)
     let attributes = try #require(document.documentAttributes)
-    #expect(attributes[PDFDocumentAttribute.creatorAttribute] as? String == "Shotdeck")
+    #expect(attributes[PDFDocumentAttribute.creatorAttribute] as? String == "Redline")
     #expect(attributes[PDFDocumentAttribute.titleAttribute] as? String == "Ben review — 2026-08-30")
     #expect(attributes[PDFDocumentAttribute.subjectAttribute] as? String == "deadbeef-dead-4eef-8ead-deadbeef0001")
     #expect(document.pageCount == 1)

Tests/ShotdeckCoreTests/ReturnWatcherTests.swift

@@ -109,6 +109,65 @@ func w25_duplicateNameSuffixIsRecognizedByScanNow() async throws {
     #expect(commented[0].fileURL.resolvingSymlinksInPath().path == pdfURL.resolvingSymlinksInPath().path)
 }
 
+@Test("W-25b Redline duplicate-name suffix is the normal AirDrop return (scanNow)")
+func w25b_redlineDuplicateNameSuffixIsRecognizedByScanNow() async throws {
+    let (paths, cleanup) = try makeCasePaths()
+    defer { try? FileManager.default.removeItem(at: cleanup) }
+
+    let ledger = try ReturnLedger(paths: paths)
+    let watcher = ReturnWatcher(paths: paths, ledger: ledger)
+    let pdfURL = paths.watchFolder.appendingPathComponent("Redline-20260830-134205 2.pdf")
+
+    try makePDF(
+        at: pdfURL,
+        pageCount: 1,
+        creator: nil,
+        subject: "44444444-4444-4444-4444-444444444444",
+        annotations: [(page: 0, annotation: makeAnnotation(
+            .ink, bounds: CGRect(x: 100, y: 100, width: 120, height: 50)
+        ))]
+    )
+
+    let found = try await watcher.scanNow()
+    #expect(found.count == 1)
+    let doc = try #require(found.first)
+    #expect(doc.fileURL.lastPathComponent == "Redline-20260830-134205 2.pdf")
+    #expect(doc.fileURL.resolvingSymlinksInPath().path == pdfURL.resolvingSymlinksInPath().path)
+    #expect(doc.pageCount == 1)
+    #expect(doc.annotatedPages == [1])
+    #expect(doc.isCommented == true)
+
+    let commented = try await ledger.commented()
+    #expect(commented.count == 1)
+    #expect(commented[0].fileURL.lastPathComponent == pdfURL.lastPathComponent)
+    #expect(commented[0].fileURL.resolvingSymlinksInPath().path == pdfURL.resolvingSymlinksInPath().path)
+}
+
+@Test("W-25c Redline creator is recognized by scanNow")
+func w25c_redlineCreatorIsRecognizedByScanNow() async throws {
+    let (paths, cleanup) = try makeCasePaths()
+    defer { try? FileManager.default.removeItem(at: cleanup) }
+
+    let ledger = try ReturnLedger(paths: paths)
+    let watcher = ReturnWatcher(paths: paths, ledger: ledger)
+    let pdfURL = paths.watchFolder.appendingPathComponent("Redline-20260830-134230.pdf")
+
+    try makePDF(
+        at: pdfURL,
+        pageCount: 1,
+        creator: "Redline",
+        annotations: [(page: 0, annotation: makeAnnotation(
+            .ink, bounds: CGRect(x: 100, y: 100, width: 120, height: 50)
+        ))]
+    )
+
+    let found = try await watcher.scanNow()
+    #expect(found.count == 1)
+    let doc = try #require(found.first)
+    #expect(doc.fileURL.lastPathComponent == "Redline-20260830-134230.pdf")
+    #expect(doc.isCommented == true)
+}
+
 @Test("W-26 Creator provenance negative at the scan level")
 func w26_presentNonShotdeckCreatorIsIgnoredByScanNow() async throws {
     let (paths, cleanup) = try makeCasePaths()

scripts/build-app.sh

@@ -11,7 +11,7 @@ cd "$ROOT"
 
 IDENTITY="Apple Development: ben@flow-master.ai (QH2H9G2LK5)"
 BUNDLE_ID="ai.flowmaster.shotdeck"
-APP_BUNDLE="${ROOT}/.build/Shotdeck.app"
+APP_BUNDLE="${ROOT}/.build/Redline.app"
 
 SKIP_SIGN=0
 for arg in "$@"; do
@@ -27,7 +27,7 @@ for arg in "$@"; do
     esac
 done
 
-echo "==> Building Shotdeck (release)"
+echo "==> Building Redline (release)"
 swift build -c release --product Shotdeck
 
 BIN_PATH="$(swift build -c release --product Shotdeck --show-bin-path)/Shotdeck"
@@ -43,6 +43,7 @@ mkdir -p "${APP_BUNDLE}/Contents/Resources"
 cp "${BIN_PATH}" "${APP_BUNDLE}/Contents/MacOS/Shotdeck"
 chmod +x "${APP_BUNDLE}/Contents/MacOS/Shotdeck"
 cp "${ROOT}/Info.plist" "${APP_BUNDLE}/Contents/Info.plist"
+cp "${ROOT}/Resources/AppIcon.icns" "${APP_BUNDLE}/Contents/Resources/AppIcon.icns"
 
 if [[ "${SKIP_SIGN}" -eq 1 ]]; then
     echo

scripts/make-dmg.sh

@@ -0,0 +1,95 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$ROOT"
+
+APP_BUNDLE="${ROOT}/.build/Redline.app"
+STAGING="${ROOT}/.build/dmg-staging"
+DMG="${ROOT}/.build/Redline.dmg"
+MOUNT_POINT="${ROOT}/.build/dmg-mnt"
+
+SKIP_SIGN=0
+for arg in "$@"; do
+    case "${arg}" in
+        --skip-sign)
+            SKIP_SIGN=1
+            ;;
+        *)
+            echo "Unknown argument: ${arg}" >&2
+            echo "Usage: $0 [--skip-sign]" >&2
+            exit 1
+            ;;
+    esac
+done
+
+echo "==> Building Redline.app"
+if [[ "${SKIP_SIGN}" -eq 1 ]]; then
+    ./scripts/build-app.sh --skip-sign
+else
+    ./scripts/build-app.sh
+fi
+
+if [[ ! -d "${APP_BUNDLE}" ]]; then
+    echo "App bundle not found at ${APP_BUNDLE}" >&2
+    exit 1
+fi
+
+echo "==> Staging DMG contents"
+rm -rf "${STAGING}"
+mkdir -p "${STAGING}"
+ditto "${APP_BUNDLE}" "${STAGING}/Redline.app"
+ln -s /Applications "${STAGING}/Applications"
+
+echo "==> Creating ${DMG}"
+mkdir -p "$(dirname "${DMG}")"
+hdiutil create -volname "Redline" -srcfolder "${STAGING}" -ov -format UDZO "${DMG}"
+
+MOUNTED=0
+detach_dmg() {
+    if [[ "${MOUNTED}" -eq 1 ]]; then
+        hdiutil detach "${MOUNT_POINT}" || hdiutil detach "${MOUNT_POINT}" -force || true
+        MOUNTED=0
+    fi
+}
+trap detach_dmg EXIT
+
+if [[ -d "${MOUNT_POINT}" ]] && /sbin/mount | grep -F -q "${MOUNT_POINT}"; then
+    hdiutil detach "${MOUNT_POINT}" || hdiutil detach "${MOUNT_POINT}" -force
+fi
+rm -rf "${MOUNT_POINT}"
+mkdir -p "${MOUNT_POINT}"
+
+echo "==> Verifying ${DMG}"
+hdiutil attach "${DMG}" -nobrowse -readonly -mountpoint "${MOUNT_POINT}"
+MOUNTED=1
+
+echo "==> Mount contents"
+ls -la "${MOUNT_POINT}"
+
+if [[ ! -d "${MOUNT_POINT}/Redline.app" ]]; then
+    echo "Verification failed: Redline.app missing from mounted DMG" >&2
+    exit 1
+fi
+if [[ ! -L "${MOUNT_POINT}/Applications" ]]; then
+    echo "Verification failed: Applications symlink missing from mounted DMG" >&2
+    exit 1
+fi
+if [[ "$(readlink "${MOUNT_POINT}/Applications")" != "/Applications" ]]; then
+    echo "Verification failed: Applications does not point at /Applications" >&2
+    exit 1
+fi
+
+echo "==> codesign --verify --deep"
+codesign --verify --deep --verbose=2 "${MOUNT_POINT}/Redline.app"
+
+echo "==> Detaching ${MOUNT_POINT}"
+hdiutil detach "${MOUNT_POINT}"
+MOUNTED=0
+trap - EXIT
+
+SHA256="$(shasum -a 256 "${DMG}" | awk '{print $1}')"
+
+echo
+echo "DMG path: ${DMG}"
+echo "SHA256: ${SHA256}"

scripts/make-icon.swift

@@ -0,0 +1,324 @@
+#!/usr/bin/env swift
+import Foundation
+import CoreGraphics
+import ImageIO
+
+// Programmatic Redline app icon.
+// Draws a 1024×1024 master, writes AppIcon.iconset (16…1024 incl. @2x),
+// and compiles Resources/AppIcon.icns via iconutil.
+//
+// Usage:
+//   swift scripts/make-icon.swift
+//   swift scripts/make-icon.swift --preview /path/to/icon-512.png
+
+private let masterSize = 1024
+
+private enum Palette {
+    static let charcoalTop = CGColor(srgbRed: 44.0 / 255.0, green: 44.0 / 255.0, blue: 46.0 / 255.0, alpha: 1)
+    static let charcoalBottom = CGColor(srgbRed: 28.0 / 255.0, green: 28.0 / 255.0, blue: 30.0 / 255.0, alpha: 1) // #1C1C1E
+    static let white = CGColor(srgbRed: 1, green: 1, blue: 1, alpha: 1)
+    static let redline = CGColor(srgbRed: 229.0 / 255.0, green: 72.0 / 255.0, blue: 63.0 / 255.0, alpha: 1) // #E5483F
+}
+
+private struct IconsetEntry {
+    let filename: String
+    let pixels: Int
+}
+
+private let iconsetEntries: [IconsetEntry] = [
+    IconsetEntry(filename: "icon_16x16.png", pixels: 16),
+    IconsetEntry(filename: "icon_16x16@2x.png", pixels: 32),
+    IconsetEntry(filename: "icon_32x32.png", pixels: 32),
+    IconsetEntry(filename: "icon_32x32@2x.png", pixels: 64),
+    IconsetEntry(filename: "icon_128x128.png", pixels: 128),
+    IconsetEntry(filename: "icon_128x128@2x.png", pixels: 256),
+    IconsetEntry(filename: "icon_256x256.png", pixels: 256),
+    IconsetEntry(filename: "icon_256x256@2x.png", pixels: 512),
+    IconsetEntry(filename: "icon_512x512.png", pixels: 512),
+    IconsetEntry(filename: "icon_512x512@2x.png", pixels: 1024),
+]
+
+// MARK: - Geometry
+
+/// Apple-style continuous-corner rounded square (squircle-like).
+/// Superellipse |x/a|^n + |y/b|^n = 1 with n≈5, inset 1px so antialiased
+/// edge pixels are not clipped by the bitmap.
+private func continuousRoundedSquare(size: CGFloat, exponent n: CGFloat = 5.0, segments: Int = 256) -> CGPath {
+    let inset: CGFloat = 1
+    let a = (size - inset * 2) / 2
+    let cx = size / 2
+    let cy = size / 2
+    let twoOverN = 2 / n
+    let path = CGMutablePath()
+    for i in 0...segments {
+        let theta = CGFloat(i) / CGFloat(segments) * 2 * .pi
+        let ct = cos(theta)
+        let st = sin(theta)
+        let x = cx + (ct < 0 ? -1 : 1) * pow(abs(ct), twoOverN) * a
+        let y = cy + (st < 0 ? -1 : 1) * pow(abs(st), twoOverN) * a
+        if i == 0 {
+            path.move(to: CGPoint(x: x, y: y))
+        } else {
+            path.addLine(to: CGPoint(x: x, y: y))
+        }
+    }
+    path.closeSubpath()
+    return path
+}
+
+// MARK: - Drawing
+
+private func drawMasterIcon(size: Int) -> CGImage {
+    let s = CGFloat(size)
+    let colorSpace = CGColorSpace(name: CGColorSpace.sRGB)!
+    let bitmapInfo = CGBitmapInfo.byteOrder32Big.rawValue | CGImageAlphaInfo.premultipliedLast.rawValue
+    guard let ctx = CGContext(
+        data: nil,
+        width: size,
+        height: size,
+        bitsPerComponent: 8,
+        bytesPerRow: 0,
+        space: colorSpace,
+        bitmapInfo: bitmapInfo
+    ) else {
+        fputs("error: failed to create \(size)×\(size) bitmap context\n", stderr)
+        exit(1)
+    }
+
+    ctx.setShouldAntialias(true)
+    ctx.setAllowsAntialiasing(true)
+    ctx.interpolationQuality = .high
+
+    // Flip to top-left origin so "top-to-bottom gradient" is literal.
+    ctx.translateBy(x: 0, y: s)
+    ctx.scaleBy(x: 1, y: -1)
+
+    ctx.clear(CGRect(x: 0, y: 0, width: s, height: s))
+
+    let squircle = continuousRoundedSquare(size: s)
+
+    ctx.saveGState()
+    ctx.addPath(squircle)
+    ctx.clip()
+
+    let gradient = CGGradient(
+        colorsSpace: colorSpace,
+        colors: [Palette.charcoalTop, Palette.charcoalBottom] as CFArray,
+        locations: [0, 1]
+    )!
+    ctx.drawLinearGradient(
+        gradient,
+        start: CGPoint(x: s / 2, y: 0),
+        end: CGPoint(x: s / 2, y: s),
+        options: [.drawsBeforeStartLocation, .drawsAfterEndLocation]
+    )
+    ctx.restoreGState()
+
+    // Viewfinder corner brackets: thick L-strokes, rounded caps/joins, inset ~18%.
+    let inset = s * 0.18
+    let bracketWidth = s * 0.095
+    let arm = s * 0.155
+    let centerline = inset + bracketWidth / 2
+
+    ctx.saveGState()
+    ctx.addPath(squircle)
+    ctx.clip()
+    ctx.setStrokeColor(Palette.white)
+    ctx.setLineWidth(bracketWidth)
+    ctx.setLineCap(.round)
+    ctx.setLineJoin(.round)
+
+    func strokeBracket(cornerX: CGFloat, cornerY: CGFloat, dirX: CGFloat, dirY: CGFloat) {
+        let path = CGMutablePath()
+        path.move(to: CGPoint(x: cornerX + dirX * arm, y: cornerY))
+        path.addLine(to: CGPoint(x: cornerX, y: cornerY))
+        path.addLine(to: CGPoint(x: cornerX, y: cornerY + dirY * arm))
+        ctx.addPath(path)
+        ctx.strokePath()
+    }
+
+    // Top-left, top-right, bottom-left, bottom-right.
+    strokeBracket(cornerX: centerline, cornerY: centerline, dirX: 1, dirY: 1)
+    strokeBracket(cornerX: s - centerline, cornerY: centerline, dirX: -1, dirY: 1)
+    strokeBracket(cornerX: centerline, cornerY: s - centerline, dirX: 1, dirY: -1)
+    strokeBracket(cornerX: s - centerline, cornerY: s - centerline, dirX: -1, dirY: -1)
+
+    // Bold redline slash over the frame, lower-left bracket area → upper-right.
+    let slashWidth = s * 0.078
+    ctx.setStrokeColor(Palette.redline)
+    ctx.setLineWidth(slashWidth)
+    ctx.setLineCap(.round)
+    ctx.setLineJoin(.round)
+    let slashInset = centerline + arm * 0.12
+    let slash = CGMutablePath()
+    slash.move(to: CGPoint(x: slashInset, y: s - slashInset))
+    slash.addLine(to: CGPoint(x: s - slashInset, y: slashInset))
+    ctx.addPath(slash)
+    ctx.strokePath()
+    ctx.restoreGState()
+
+    guard let image = ctx.makeImage() else {
+        fputs("error: failed to materialize master CGImage\n", stderr)
+        exit(1)
+    }
+    return image
+}
+
+private func scaledImage(_ image: CGImage, pixels: Int) -> CGImage {
+    if image.width == pixels && image.height == pixels {
+        return image
+    }
+    let colorSpace = CGColorSpace(name: CGColorSpace.sRGB)!
+    let bitmapInfo = CGBitmapInfo.byteOrder32Big.rawValue | CGImageAlphaInfo.premultipliedLast.rawValue
+    guard let ctx = CGContext(
+        data: nil,
+        width: pixels,
+        height: pixels,
+        bitsPerComponent: 8,
+        bytesPerRow: 0,
+        space: colorSpace,
+        bitmapInfo: bitmapInfo
+    ) else {
+        fputs("error: failed to create \(pixels)×\(pixels) scale context\n", stderr)
+        exit(1)
+    }
+    ctx.interpolationQuality = .high
+    ctx.setShouldAntialias(true)
+    ctx.draw(image, in: CGRect(x: 0, y: 0, width: pixels, height: pixels))
+    guard let out = ctx.makeImage() else {
+        fputs("error: failed to scale image to \(pixels)px\n", stderr)
+        exit(1)
+    }
+    return out
+}
+
+private func writePNG(_ image: CGImage, to url: URL) {
+    let dir = url.deletingLastPathComponent()
+    try? FileManager.default.createDirectory(at: dir, withIntermediateDirectories: true)
+    if FileManager.default.fileExists(atPath: url.path) {
+        try? FileManager.default.removeItem(at: url)
+    }
+    guard let dest = CGImageDestinationCreateWithURL(url as CFURL, "public.png" as CFString, 1, nil) else {
+        fputs("error: cannot create PNG destination at \(url.path)\n", stderr)
+        exit(1)
+    }
+    CGImageDestinationAddImage(dest, image, nil)
+    if !CGImageDestinationFinalize(dest) {
+        fputs("error: failed to write PNG \(url.path)\n", stderr)
+        exit(1)
+    }
+}
+
+// MARK: - Paths / CLI
+
+private func repoRoot() -> URL {
+    let cwd = URL(fileURLWithPath: FileManager.default.currentDirectoryPath, isDirectory: true)
+    let arg0 = URL(fileURLWithPath: CommandLine.arguments[0])
+    let scriptURL: URL
+    if arg0.path.hasPrefix("/") {
+        scriptURL = arg0.standardizedFileURL
+    } else {
+        scriptURL = cwd.appendingPathComponent(arg0.path).standardizedFileURL
+    }
+    let fromScript = scriptURL.deletingLastPathComponent().deletingLastPathComponent()
+    if FileManager.default.fileExists(atPath: fromScript.appendingPathComponent("Package.swift").path) {
+        return fromScript
+    }
+    if FileManager.default.fileExists(atPath: cwd.appendingPathComponent("Package.swift").path) {
+        return cwd
+    }
+    fputs("error: could not find repo root (Package.swift)\n", stderr)
+    exit(1)
+}
+
+private func parsePreviewPath() -> String? {
+    let args = CommandLine.arguments
+    var i = 1
+    var preview: String?
+    while i < args.count {
+        let arg = args[i]
+        if arg == "--preview" {
+            i += 1
+            guard i < args.count else {
+                fputs("error: --preview requires a path\n", stderr)
+                exit(1)
+            }
+            preview = args[i]
+        } else if arg.hasPrefix("--preview=") {
+            preview = String(arg.dropFirst("--preview=".count))
+        } else if arg == "--help" || arg == "-h" {
+            fputs("Usage: swift scripts/make-icon.swift [--preview PATH]\n", stderr)
+            exit(0)
+        } else {
+            fputs("error: unknown argument \(arg)\n", stderr)
+            fputs("Usage: swift scripts/make-icon.swift [--preview PATH]\n", stderr)
+            exit(1)
+        }
+        i += 1
+    }
+    return preview
+}
+
+private func runIconutil(iconset: URL, icns: URL) {
+    let proc = Process()
+    proc.executableURL = URL(fileURLWithPath: "/usr/bin/iconutil")
+    proc.arguments = ["-c", "icns", iconset.path, "-o", icns.path]
+    proc.standardOutput = FileHandle.standardOutput
+    proc.standardError = FileHandle.standardError
+    do {
+        try proc.run()
+        proc.waitUntilExit()
+    } catch {
+        fputs("error: failed to launch iconutil: \(error)\n", stderr)
+        exit(1)
+    }
+    if proc.terminationStatus != 0 {
+        fputs("error: iconutil exited \(proc.terminationStatus)\n", stderr)
+        exit(1)
+    }
+}
+
+// MARK: - Main
+
+let root = repoRoot()
+let resources = root.appendingPathComponent("Resources", isDirectory: true)
+let icnsURL = resources.appendingPathComponent("AppIcon.icns")
+let previewPath = parsePreviewPath()
+let fm = FileManager.default
+
+print("==> Drawing \(masterSize)×\(masterSize) master")
+let master = drawMasterIcon(size: masterSize)
+
+let iconset = fm.temporaryDirectory.appendingPathComponent("Redline-AppIcon-\(UUID().uuidString).iconset", isDirectory: true)
+
+do {
+    try fm.createDirectory(at: iconset, withIntermediateDirectories: true)
+    try fm.createDirectory(at: resources, withIntermediateDirectories: true)
+
+    print("==> Writing AppIcon.iconset")
+    for entry in iconsetEntries {
+        let img = scaledImage(master, pixels: entry.pixels)
+        writePNG(img, to: iconset.appendingPathComponent(entry.filename))
+    }
+
+    if fm.fileExists(atPath: icnsURL.path) {
+        try fm.removeItem(at: icnsURL)
+    }
+
+    print("==> Compiling \(icnsURL.path)")
+    runIconutil(iconset: iconset, icns: icnsURL)
+
+    try? fm.removeItem(at: iconset)
+} catch {
+    try? fm.removeItem(at: iconset)
+    fputs("error: \(error)\n", stderr)
+    exit(1)
+}
+
+if let previewPath {
+    let previewURL = URL(fileURLWithPath: previewPath)
+    print("==> Writing 512px preview \(previewURL.path)")
+    writePNG(scaledImage(master, pixels: 512), to: previewURL)
+}
+
+print("App icon: \(icnsURL.path)")